铁基超导体为理解高温超导机制提供了新的机遇，在该体系中配对机制被认为与磁涨落密切相关，因此母体中磁性的起源成为研究的焦点。铁基超导体中"11"相以其简单的结构、不含毒性元素砷等特点引起了广泛关注。关于其母体FeTe磁性的起源问题还没有定论：一方面，Fe1+yTe与铁砷超导体母体具有相同的铁格子和类似的费米面，但却表现出与其费米面嵌套引起的自旋密度波磁性不同的磁结构；另一方面，密度泛函计算预言在FeTe（不含过量铁）中存在与铁砷母体相同的费米面嵌套，而且中子散射实验也表明"11"相与铁砷超导体具有相同的超导自旋共振。 导致上述复杂情况的原因是FeTe磁性灵敏地依赖于组分、微结构等性质。本项目通过Te位元素替代、不同气氛条件下退火、外加压力等手段调节FeTe的组分、微结构等，研究磁性与其之间的相互作用，探索"11" 相磁性起源问题，并尝试合成FeTe相关的新型超导材料。

The iron-based superconductors open up a new way to investigate the mechanism of high-temperature superconductivity. In this system, the magnetic fluctuation is considered to play a key role in mediating superconductivity. Therefore the magnetic origin in parent compounds is one of the most important problems. Among iron-based superconductors, the '11' phase family with the simplest structure and without toxic arsenic element has attracted intense interest. The origin of magnetism in parent compound of this family is unsettled at present: On the one hand, the parent compound Fe1+yTe shares the same Fe building block and the similar Fermi surface topology with iron arsenides, but exhibits different magnetic order from the spin-intensity-wave magnetism in iron arsenides induced by Fermi surface nesting. On the other hand, the same Fermi surface nesting as in iron arsenides is predicted in undoped FeTe by density functional theory calculations. Moreover neutron scattering study reveals the same superconducting spin resonance in '11' family and the iron arsenide superconductors. This complexity is due to the sensitive dependence of magnetism in FeTe upon composition, microstructure and etc. In this project, we plan to investigate the interplay between magnetism and composition or microstructure, through substituting elements for Te, annealing FeTe in various atmospheres and applying pressure on samples. This project is aimed at exploring the magnetic origin in the '11' family, as well as searching new FeTe-related superconducting materials.